Exercise device



FIG. 1 is a perspective view of an exercise device;

FIG. 2 is a front side view thereof, a rear side being a mirror image of the front side;

FIG. 3 is a top view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a bottom view thereof.

The broken lines are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for an exercise device, as shown and described. 